What is the molarity of a solution that contains 3.25 moles of NaNO_3 in 250. mL of solution?

• A. 0.770 M
• B. 13.0 M
• C. 0.0130 M
• D. 8.13 M

Answer: (B)

Verified step by step guidance

1. Identify the formula for molarity, which is defined as moles of solute divided by liters of solution: \(M = \frac{\text{moles of solute}}{\text{liters of solution}}\).
2. Convert the volume of the solution from milliliters to liters because molarity requires liters. Use the conversion factor: \$1\, \text{L} = 1000\, \text{mL}\(. So, \)250.\, \text{mL} = \frac{250.}{1000} = 0.250\, \text{L}$.
3. Plug the given values into the molarity formula: moles of NaNO\(_3\) is 3.25 moles, and volume is 0.250 L.
4. Calculate the molarity by dividing the moles of solute by the volume in liters: \(M = \frac{3.25}{0.250}\).
5. Interpret the result as the molarity of the NaNO\(_3\) solution, which tells you how many moles of NaNO\(_3\) are present per liter of solution.